Hazard Scale of the Day: After a particularly nasty natural disaster, there is one reliable metric that FEMA turns to in order to determine the severity of the damage: The “Waffle House Index.”

Green indicates that Waffle Houses in the affected area are serving a full menu, meaning that the damage is limited. Yellow signals more extensive damage, resulting in a limited menu (the generators are on and food supplies are low).

Finally, red means severe damage has forced the restaurant to close its doors — something the Waffle House prides itself on doing very rarely. In fact, all but one of the 22 Waffle Houses that lost power during Hurricane Irene were up and running by Wednesday evening.

“If you get there and the Waffle House is closed?,” says FEMA Administrator Craig Fugate, “that’s really bad. That’s where you go to work.”